Patterning mechanism for circular knitting machines

ABSTRACT

A circular knitting machine with stationary needle cylinder and revolving cam box is equipped with patterning units which rotate with the cam box and each comprises needle selector members and actuators therefor. Solenoids at stationary location selectively operate the actuators. Electronic switches control solenoid energization. Photoelectric cells, selectively influenced by an intermittently movable control film, dictate selective preconditioning (opening) of electronic switches in readiness for closure of same to pulse selected solenoids. A timer closes preconditioned switches for a preset time so energizing the solenoids for the same time. A reed switch operable in time with the cam box controls the timer.

Inventors Appl. No.

Filed Patented Assignee Priority Ernest L. Farmer Leicester;

Bertram Johnson, Braunstone, both of, England July 29, 1968 June 22, 1971 Wildt Mellor Bromley Limited Leicester, England Aug. 4, 1967 Great Britain PA'I'IERNING MECHANISM FOR CIRCULAR KNITTING MACHINES 7 Claims,

1/ 1956 Thurston 5/1963 Thurston 9 Drawing Figs.

References Cited UNITED STATES PATENTS 3,229,482 1/1966 Farmer 66/50 3,313,128 4/1967 Schmidt et al.... 66/154 (A)X 3,313,129 4/1967 Stock 66/50 (A) X 3,423,960 1/1969 Wiesinger et a1. 66/154 (A) X 3,449,928 6/1969 Schmidt et a1. 66/50 OTHER REFERENCES ENGINEER S RELAY HANDBOOK, 1966, Hayden Book Co., Inc., New York, pp. 67- 70, Patent Office Scientific Library TX 2861 N2.

Primary ExaminerWm. Carter Reynolds Attorney-Larson, Taylor & Hinds ABSTRACT: A circular knitting machine with stationary needle cylinder and revolving cam box is equipped with patteming units which rotate with the cam box and each comprises needle selector members and actuators therefor. Solenoids at stationary location selectively operate the actuators. Electronic switches control solenoid energization. Photoelectric cells, selectively influenced by an intermittently movable control film, dictate selective preconditioning (opening) of electronic switches in readiness for closure of same to pulse selected solenoids. A timer closes preconditioned switches for a preset time so energizing the solenoids for the same time. A reed switch operable in time with the cam box controls the timer.

PATENTED JUH22I97I SHEET 2 BF 6 PAWEN TED JUN 22 W1 SHEET 5 [IF 6 IA'I'IERNING MECHANISM FOR CIRCULAR KNITTING MACHINES This invention relates to circular knitting machines of the revolving cam box type, and has reference exclusively to such a machine equipped with a patterning system of the kind comprising, in combination, (a) a plurality of patterning units rotating in unison with the revolving cam box, each of these units including a stack of individually movable selector members adapted for action selectively upon butts either on needles, or on associated jacks, sliders or the like in a stationary needle cylinder for the purpose of actuating needles selectively in conjunction with a corresponding stack of actuators for selectively actuating the individually movable selector members of the unit, and (b) pattern controlled programming means at a stationary location comprising a bank of solenoids for effecting selective actuation of the aforementioned actuators and a control for the solenoids including a relatively thin and flexible film, band or tape which is movable intermittently in time with the rotary motion of the cam box and has formed therein dispositions of holes predetermined in accordance with the pattern it is desired to produce in the fabric being knitted, the apertured and unapertured portions of the control film, band or tape being designed to influence the operation of switch means arranged in circuitry incorporating the solenoids.

It is to be clearly understood that the term holes" is used in respect of the film, band or tape in a generic sense sufficiently broad to cover a light-transmitting point which although in the nature of a transparent or translucent window is not actually apertured. Accordingly, the phase apertured and unapertured portions of the control film, band or tape" is to be interpreted, where the context so admits, as meaning points which respectively transmit and mask light.

In a patterning system of this kind the bank of solenoids effects selective actuation seriatim of the plurality of stacks of actuators, and through them, also the corresponding stacks of individually movable selector members which stacks are grouped around a stationary needle cylinder and arranged to rotate in unison with the associated rotary cam box of the machine.

Heretofore, a difiiculty experienced with a patterning system of the kind herein referred to is that, due to the speed at which the circular knitting machine is operating, there is no precision in the timing of the energization periods of each solenoid. In particular there is no guarantee of the lengths of time for which each solenoid is energized. This in turn, has led to uncertainty in the accuracy of the control exercised by the programming means.

The object of the present invention is to provide, in the pattern controlled programming means of a patterning system of the kind concerned, improved and efficient switch means designed to overcome the foregoing difficulty.

According to the characteristic feature of this invention the energization of solenoids of the stationary bank is controlled by corresponding electronic switch devices which are selectively preconditioned (in readiness for being rendered operative) at the dictates of selectively influenced electrical means controlled by the control film, band or tape and, for rendering the selected switch devices operative and as a consequence energizing the corresponding solenoids for a preset length of time, there is provided a timer adapted to be controlled by a reed switch regularly operated in timed relation with the operation of the circular knitting machine.

It is principally the intention that the timer shall operate electronically, the idea being that the length of time during which a selected solenoid is energized at each energization thereof shall be precisely determined by the judiciously chosen characteristics of the said timer.

In a convenient embodiment of the invention, the solenoids of the stationary bank are each connected with one of a corresponding group of electronic switch devices which are adapted to be preliminarily set selectively in their open positions by appropriate selective activation of corresponding electroresponsive devices arranged to be suitably influenced by the intermittently movable control film, band or tape.

In order that the invention may be more clearly understood and readily carriedinto practical effect, a specific example thereof will now be described with reference to the accompanying drawings, wherein,

FIG. 1 is a vertical cross-sectional view of so much of a circular knitting machine of the revolving cam box type as is sufficient to illustrate the .application of the invention thereto, and includes, in side elevation, one of the revolving patterning units, the relatively stationary pattern controlled programming means and the reed switch casing,

FIG. 2 is a plan view corresponding to FIG. 1,

FIG. 3 is a side view, partly in section, of the drum over which the control film, band or tape is passed, and shows also some of the electroresponsive devices arranged to be influenced by the said film, band or tape,

FIG. 4 is a detail cross-sectional view taken on the line IV-IV of FIG. 3,

FIG. 5 is a vertical sectional view taken on the'line V-V of FIG. 2 illustrating, inter alia, a rotary magnet system for actuating the reed switch and an associated gearbox included in the means for driving such magnet system,

FIGS. 6a and 6b show two detail operational views depicting elements through the medium of which a solenoid effects selective actuation of actuators for the selector members,

FIG. 7 is a plan view of the reed switch and of the rotary magnet system for operating the same,

FIG. 8 is a block diagram illustrating the relationship of a solenoid to the corresponding electronic switch device, the related electroresponsive device, the timer and the reed switch.

Merely by way of example, the invention is shown as applied to a circular knitting machine of the double axially opposed needle cylinder type comprising upper and lower needle cylinders furnished with a set of doubleended latch needles some or all of which are transferable up and down from one cylinder to the other, according to knitting requirements. Thus, the portion of such a machine shown in FIG. 1 includes a stationary lower needle cylinder 1, a double-ended latch needle 2 and a needle-actuating slider 3 whereby knitting and transfer movements are imparted to the said needle. At 4 is designated a revolving cam box fitted with slider cam systems 5. This cam box is secured upon columns 6 of a framework which is in turn mounted upon a revolving cam box carriage 7. The latter, of annular form, revolves within a complementarily shaped recess 8 formed in the middle bed plate 9 of the machine. The annular carriage 7 is provided with a gear 7a with which is arranged to mesh a pinion (not shown) driven from a plain drive. Depending from, and secured by screws 10 to, the lower needle cylinder 1 is a coaxial stationary jack cylinder 11 tricked to receive slider-controlling jacks such as I2. The

cylinder contains a full complement of needles 2 and sliders 3. Likewise, the cylinder I1 contains a full complement of jacks l2 and jack selectors 13. Each jack selector 13 is mounted to rock inwardly and outwardly in its trick and is provided with a lower butt I4. The upper end of each such jack selector 13 is arranged for action on a shoulder 120 on the corresponding jack 12. The arrangement is such that whenever the lower end of a rocking jack selector 13 is pressed inwardly into the jack cylinder 11, its lower butt 14 will be moved clear of the path of a jack raising cam 15, attached to the revolving cam box carriage 7, with the result that this jack selector and the corresponding jack I2, slider 3 and needle 2 will all fail to be raised. Conversely, if a jack selector 13 is not pressed in, its lower butt 14 will be left in an outward position so that it will be acted upon by the jack raising cam 15 and elevated to raise the corresponding jack l2, slider 3 and needle 2. It is in this manner that the double-ended needles 2 (when in the lower cylinder 1) are actuated selectively, e.g. for knitting or for transfer upwardly.

To enable them to be pressed in selectively, the rocking jack selectors 13 are formed with patterning butts 13a disposed in a multiplicity of superimposed planes so as to enable the butts in any one plane to be spaced apart with appropriate circumferential distances, and hence also time intervals, between them. lnitially, each of the jack selectors may be formed with a full complement of the patterning butts ll3a which are broken away where required. The jack selectors 13, each with a patterning butt 11311 in a predetermined position thereon, are in fact prearranged in the cylinder it so as to provide around the latter circumferentially spaced obliquely disposed parallel lines of the said patterning butts.

The machine is provided with a plurality of patterning units such as PU mounted upon the columns 6 and thus rotating in unison with the revolving cam box 4, the purpose of each such unit being to press in the rocking jack selectors l3 selectively. Each patterning unit is attached by screws to the corresponding column 6, and the latter is affixed to the revolving cam box carriage 7 by means of screws one of which is indicated at ll6 in FIG. 2. Each of the units PU includes a bracket l7 formed to receive a stack of superimposed and individually movable selector members 18 in the form of independent horizontally disposed presser slides adapted for action selectively upon the patterning butts ll3a. There are, of course, as many of the presser slides m in the stack as there are patterning butts 13a in each obliquely disposed line thereof. in conjunction with the presser slides W of each unit lPU there is a corresponding stack of actuators 19 for selectively actuating the said slides. The actuators 19 are in the form of individually tumable auxiliary actuating levers-one to each presser slide lib.

At a stationary location on the middle bed plate 9 there is provided a bank of solenoids S for effecting selective actuation of the auxiliary actuating levers H9, and a control for these solenoids including a film F (see H08. 2 and 3) which is movable intermittently in time with the rotary motion of the cam box t. The film has formed therein dispositions of holes 20 predetermined in accordance with the pattern to be produced, the apertured and unapertured portions of the control film influencing the operation of switch means arranged in circuitry incorporating the solenoids S, as will be hereinafter described. The solenoids S in the bank are selectively ener' gized a number of times per revolution of the cam box corresponding to the number of patterning units revolving therewith.

Preferably, each of the said patterning units PU is of a previously proposed form. That is to say, each of said units preferably includes a tumable catch lever 21 (HO. 2) which is common to all of the actuating levers H9 in the relevant stack and is operable, at each reselection of these levers, first in one sense to permit of release of previously selected ones for return, under the action of a biassing influence to their nonoperable positions, and then in the reverse sense to function as a check pawl to maintain the newly selected actuating levers in their operative positions against the action of such a biassing influence. Moreover, the common tumable catch lever 23 is engageable with and disengageable from the auxiliary actuating levers H9 and the operative ends of the latter have cam portions 1911 with suitably profiled edges for direct engagement with thetail ends of the respective presser slides 18, whereby whenever selected auxiliary actuating levers are turned from their inoperative into their operative positions at the dictates of the pattern controlled programming means (presently to be described), the cam portions 19a of these levers will act on the tail ends of the corresponding presser slides 18 and push the latter smoothly and accurately into their operative positions.

Advantageously, each of said auxiliary actuating levers 19 may be controlled by a spring against the influence of which the lever is turned into its operative position and under the influence of which the lever is returned to its inoperative position when it is released as a consequence of disengagement of the catch lever 21 therefrom. Incidentally, in FIG. 2, one of the levers 119 is shown both in its inoperative position (dotted lines) and also in its operative position (mainly full lines). An appropriate edge portion of each of these auxiliary actuating levers rs, moreover, has formed therein a suitably shaped recess 11% so disposed as to be presented opposite to the catch lever 2t whenever the said auxiliary lever is selected and turned into its operative position. Preferably, this recess 11% is located adjacent to the cam portion 191: of the lever. In any event, the edge portion of the auxiliary actuating lever 19 adjoining the recess ll9b also requires to be so inwardly shaped as to accommodate the catch lever 21 even when the auxiliary lever is in its inoperative position. Each turnable auxiliary actuating lever 19 is furnished with a radially extending tail 19c arranged to be acted upon at relevant times by a corresponding one of a bank of fulcrummed programming levers 23 of bellcrank form. Each such programming lever has a first arm 23a formed with a protuberant nose 23b which whenever the said lever is turned, as viewed in FIG. 2, in an anticlockwise direction into an operative position and is allowed to remain in that position, strikes the tail of the auxiliary actuating lever l9 which is in the same plane. This action renders the lever H9 operative in a selective manner and thereby pushes in the corresponding presser slide 18, against the action of its springs 22, with the result that any rocking jack selectors 113 with patterning butts 33a in the relevant plane will be pressed inwardly so that their bottom butts 114 will miss the raising cam R5. The programming levers 23 are mounted for individual turning movement about a common vertical fulcrum pin 24, and each is controlled by a tension spring 25 normally functioning to urge the lever into its inoperative position. Each programming lever 23, moreover, has a second arm 23: the extremity of which is appropriately formed for cooperation at relevant times with a linearly movable and suitably guided interrupter latch 26. There is one interrupter latch 26 to each solenoid S. For economy in space, the solenoids of the bank are divided, as shown in FIG. 2, into a plurality of relatively staggered groups, the latches 26 being so disposed that each can be readily acted upon by its corresponding solenoid.

As will be seen more clearly in FlG. 6, each interrupter latch 26 is rabbetted at one end, as indicated at 260, to receive and retain, with a latching action, the outer end of the second arm 23c of the corresponding programming lever 23. The opposite end of each latch 26 is provided with a tail portion 26!: adapted to be acted upon by the axially projected core 27 of a pulsed solenoid S.

Merely for convenience in illustration, only one of the subgroups of the total number of solenoids in the bank is shown in FIG. H, and in this same figure the number of latches 26 shown, although greater than that of the solenoids is less than that of the programming levers: but in practice, of course, there will be the same number of programming levers as there are latches and solenoids. in any event, there is, in the example being described, a preselection movement of all of the programming levers 23} whereby they are all swung anticlockwise (as viewed in FIG. 2) into their operative positions, immediately preparatory to a selective energization of the solenoids S of the bank. Then, as the result of such selective energization of the solenoids S, controlled from the aforementioned film F, the interrupter latches 26 corresponding to the pulsed solenoids will be projected forwardly by the cores 27 until their rabbetted portions 260 engage the outer edges of the arms 23c of the relevant programming levers to latch and thus retain the latter in the operative positions to which they were previously moved (see a(FlG. 6). On the other hand, those interrupter latches 26 corresponding to solenoids which are not pulsed will not be projected forwards as a consequence of which the relevant programming levers will be permitted to return to their normal inoperative positions under the influence of their springs 25, in which positions of the said levers their noses 23!; will be withdrawn so that relevant ones of the auxiliary actuating levers 19 will not be turned to move forward the corresponding presser slides.

Before describing the beater means employed to effect such a preselection movement of all of the programming levers 23, it will be convenient to define, initially in broad terms, the characteristic feature of the present invention. Thus, in accordance with the invention as applied to the illustrated example, the energization of the solenoids S of the stationary bank is controlled by corresponding electronic switch devices in the form of thyristors 28 (FIG. 8) which are selectively preconditioned by virtue of being caused to assume their ready positions (in readiness for being fired or triggered to energize the corresponding solenoids S) at the dictates of selectively influenced electroresponsive devices in the form of photoelectric (RB) cells 29 controlled by the film F; for firing or triggering the selected, i.e. ready, thyristors 28-one per P.E. cell 29-and as a consequence energizing the corresponding solenoids S for a preset length of time, there is provided an electronic timer T adapted to be controlled by a reed switch RS regularly operated in timed relation with the rotation of the cam box carriage 7.

The reed switch RS is of the single-pole changeover type and comprises a long, magnetic reed movable between two fixed contacts-all hermetically sealed in a glass tube 30. The long reed is mechanically biassed to one contact (nonmagnetic), and changeover is made to the other contact (magnetic) when the switch is actuated. The changeover takes place when a sufficiently strong external magnetic force is applied. The long reed springs over to the nonmagnetic contact when the magnetic field is removed.

In carrying out the present invention, the reed switch RS is stationarily held adjacent to a rotary component 31 which is driven in time with the machine and carries a'plurality of magnets such as 32 for influencing said switch. The actual reed switch RS and the adjacent rotary component 31 are accommodated in a cylindrical casing 33 fitted with a lid or cover 34. The rotary component 31 is rigidly secured upon the upper end of a vertical spindle 35 which, as shown in FIG. 5, is mounted for rotation in bearings 36 provided centrally within a gearbox 37 having a cover 37a. Keyed to the spindle 35 is a gear 38 which is arranged to be driven at an appropriate speed related to that of the cam box 4 from the aforesaid gear 7a, through the medium of intermediate coaxial gears or pinions 39, 40 (see FIG. 2).

The aforementioned beater means employed to move all of the programming levers 23 to their operative positions, immediately prior to each selective energization of the solenoids S, include a vertically disposed beater bar 41, common to all of the said levers, this beater bar being attached by means of screws 42 to suitably spaced upper and lower pivoted levers 43 and 44 which are attached or keyed to the respectively upper and lower ends of the vertical fulcrum pin 24. The said upper and lower ends of the pin 24 are joumaled in bearings such as 45 set in a bracket 46 supporting the pattern controlled programming means. The beater bar 41, which is influenced by tension springs such as 47 (FIG. 2) is arranged for action upon the second arm 23c of all of the programming levers 23 simultaneously. For actuating the said heater bar 41, in appropriate timed relation with the remaining mechanism, there is provided a rotary cam 48 which, as depicted in FIG. 5, is secured by dowels 49 upon the gear 38. This cam acts on a roller 50 carried by one end of a slide 51 which is mounted for linear movement slidably within a radial extension 37b of the gearbox 37. The opposite end of this slide 51 is furnished with another roller 51 arranged in direct contact with the beater bar 41. Thus, the cam 48 swings the said beater bar in the anticlockwise direction (as viewed in FIG. 2), against the action of the spring 47, and the latter swings the bar in the clockwise direction under the control of the cam.

For returning projected interrupter latches 26 to their original positions after each selective energization of the solenoids S, in readiness for the next similar actuation of such solenoids, there is provided a latch return beater 53in the form of a vertical bar common to all of the latches and arranged for action upon the ends 260 of the latter. The latch return beater 53 is carried by upper and lower arms 53a which are secured to a vertical spindle 54 joumaled in appropriate parts of the aforementioned bracket 46. The beater 53 is controlled by a torsion spring 55 (see FIG. I). Actuation of the latch return beater 53 is effected from a rotary cam 56 which is dowelled to the underside of the gear 38 and is arranged for action upon a roller 57 carried by another slide 58 movable within the radial extension 37b of the gearbox 37. The slide 58 acts upon a depending pin 59 set in a pivoted lever 60. Thus, whenever the slide 58 is moved outwardly by the cam 56, it turns the lever 60 in an anticlockwise direction (FIG. 2) so that this lever acts on and swings the beater 53 in a clockwise direction for action upon the ends 26c of the interrupter latches 26.

The film F has formed in its lateral margins longitudinal rows of suitably spaced sprocket holes 61 which engage with corresponding spaced pins 62 set in intermittently rotatable end portions 63a and 63b of a film drum FD having an intermediate stationary portion 63c of hollow cylindrical form. The two end portions 63a and 63b of the film drum are rigidly keyed upon and thus connected by a central intermittently tumable spindle 64 which is joumaled in a film drum support bracket 65. This bracket is attached by screws 66 to the underside of the bed plate 9. One end of the spindle 64 extends through the drum portion 63b and has rigidly secured thereon a ratchet wheel 67 arranged to cooperate with a pawl 68 (FIG. 2) operable from the machine in suitable timed relation therewith. The main intermediate stationary portion 63c of the film drum FD has end plates 69 to support a horizontal hollow shaft 70 which is in turn supported upon the spindle 64. A radially extending adjustable pin 71 fixed in the bracket 65 extends through the wall of the stationary drum portion 630 and engages in an aperture 700 (FIG. 3) formed in the hollow shaft 70 for the purpose of positively preventing any rotation of the said drum portion.

As shown in FIG. 4, the intermediate stationary portion 630 of the film drum FD is made in two halves secured together by screws 72. Formed in the upper half of this stationary drum portion is a straight axially extending row of holes 73 disposed in alignment with the longitudinal series of the holes 20 in the film F. The P.E. cells 29, of which each is connected separately to one of the auxiliary thyristors 28 (FIG. 8), are secured in the holes 73. At 74 is indicated wiring from the PE. cells to the thyristors located in an electronic control box 75. This box also incorporates, inter alia, the electronic timer T with which the P.E. cells are suitably associated. Incidentally, for the sake of simplicity, only one of these thyristors is shown and then only in a purely diagrammatic box form (see FIG. 8).

On the outside of the film drum FD is provided, in a casing 76, a single light-radiating tube 77 arranged opposite to the axial row of holes 73 in which the RE. cells 29 are set. Alternatively, the single tube 77 could be replaced by a single row of individual light bulbsone to each P.E. cell. The arrangement is accordingly such that each time a fresh transverse row of holes 20 in the film F is brought by racking the drum portions 63a and 63b, into register with the axial row of holes 73 in the drum, and thus opposite to the P.E. cells, those cells which are in line with holes 20 in the film will be activated, i.e. given a short pulse of energy, by the light permitted to shine therethrough, whereas those P.E. cells which are opposite to unapertured portions of the film will be masked from light and not so activated.

In an alternative arrangement, however, the source or sources of light may be disposed on the inside and the RB. cells on the outside of the film drum. Moreover, it would be possible, if so desired, to reverse the mode of operation of the PE. cells so that they are normally illuminated and are only cut off from the relevant source or sources of light selectively when they are required to open the corresponding thyristors. Accordingly, the said P.E. cells can be broadly regarded as being suitably influenced to precondition corresponding thyristors by the occurrence adjacent thereto, at each appropriate phase of operation of the machine, of apertures in, or unapertured portions of, the control film F, depending on the mode of operation adopted. The thyristors 28 are fed with DC. current and are also in the nature of memory devices. Thus, whilst short pulses of energy given to the selected P.E. cells 29 enable them to read the relevant control data on the film F, the corresponding thyristors 28 remember" this reading after the cells have read and the transistor pulse begins, thereby enabling the film to be racked on.

The electronic timer T into the circuitry of which is incorporated the reed switch RS (FIG. 8) is controlled by closure and opening of this switch in timed relation with the operation of the machine. Conveniently, and as diagrammatically shown in FIG. 3 the timer T comprises a capacitor C and a resistance R wired in circuit with a transistor TR, the electronic circuitry being such that each time the reed switch R5 is connected to a supply line, the capacitor C is charged but when this switch is next released and connected to resistor R and transistor TR the capacitor will discharge into the transistor thereby per-- mitting to pass through the transistor TR a power pulse which fires or triggers the previously opened thyristors 28 and so energizes the corresponding solenoids S. The capacitor C discharges into the transistor TR and so effects energization of the selected solenoids for definite preset length of time determined by the capacitor/voltage/resistance characteristic. This time period starts from the time that the capacitor is switched in and continues to a certain point in the decay of current from the capacitor.

Assume, merely by way of example, that the circular knitting machine concerned is equipped with six patterning units PU each as herein defined. Then the rotary component 31 may carry three of the magnets 32 and be caused to rotate to the extent of two revolutions for each revolution of the rotary cam box 3. In such a case, in the same period, the control film F will be racked six times. Thus, with the machine operating at 20 r.p.m. there will be 120 operations of the reed switch RS per minute, giving half a second for each selection of a solenoid.

The block diagram of FIG. 8 will enable the reader to more readily follow how the energization of the solenoids S is effected by the thyristors at the dictates of P.E. cells controlled by the film F, and how the timer T, controlled by the reed switch RS, determines the preset length of time for which the solenoids are energized.

At 78 in FlGS. l and 2 are depicted printed circuit plug boards, a two-way connector socket being also shown at 79 in FIG. E. in FIG. 2, moreover, sheathed wiring to the control box '75 is indicated at M.

Referring again to the turnable catch lever 2Il of each patterning unit PU, it should be explained that a release shaft for said catch lever is indicated at M in FIGS. ll and 2. This shaft is rigidly secured to a common carrier bar 2H serving to carry the catch lever 21. A torsion spring 82 controls the shaft 8B which latter has mounted on its upper end a release lever 83. A striker (not shown) is provided at a stationary location on the machine for action upon the release lever 83 at appropriate times. Thus, whenever the release lever 83 is struck, the catch lever 21 will be turned, against the action of the torsion spring $2, to release the relevant auxiliary actuating levers 119 of the unit for return to their inoperative positions, all as hereinbefore explained.

In an appropriate case there may be provided in one and the same machine two control drums and thus two films, band or tapes for controlling two selection stations per feed, in which case the machine would be fitted with two reed switches arranged to be successively operated. Either or both of the said two drums may be racked at each appropriate control phase.

We claim:

l. A circular knitting machine comprising, in combination, a stationary tricked cylinder; knitting instruments in said cylinder having butts thereon; a cam box revolvable about said cylinder and fitted with cams for actuating the knitting instruments; a plurality of patterning units rotatable in unison with said cam box, each of these units including a stack of individually movable selector members for action selectively upon the aforesaid butts for actuating knitting instruments selectively, and a corresponding stack of actuators for selectively actuating the selector members of the unit; a bank of solenoids at a stationary location for effecting selective actuation of the actuators; switch means arranged in circuitry incorporating the solenoids; a relatively thin and flexible control film having formed therein dispositions of holes predetermined in accordance with the pattern it is desired to produce on the machine; and means for intermittently moving said control film in time with the rotary cam box suchwise that the apertured and unapertured portions of the film influence the operation of said switch means, wherein the improvement resides in the provision in the machine of electronic thyristor switch devices for controlling energization of the corresponding solenoids; photoelectric cells arranged to sense holes in the film to dictate selective preconditioning of the said electronic thyristor devices, in readiness for their being rendered operative to cause a pulse of current to be passed to the solenoids, wherein there is provided a separate photoelectric cell and a separate thyristor device for each solenoid, a timer circuit for rendering the selectively preconditioned electronic thyristor switch devices operative for a preset length of time and as a consequence energizing the solenoids for the same length of time; and a reed switch which is regularly operated in timed relation with the rotary motion of the cam box for controlling the said timer circuit.

2. A circular knitting machine according to claim l, which includes a rotary component carrying a plurality of magnets, and gearing between a rotary cam box carriage and said rotary component for driving the latter in time with the rotary mo tion of the cam box, the reed switch being stationarily located and held adjacent to the rotary component so that it is influenced by the magnets.

3. A circular knitting machine according to claim 11, which includes a bank of selectively movable programming levers each movable into an operative position in which it can strike and render operative a corresponding actuator of a selector member; a corresponding number of latches arranged to be selectively projected by selectively energized solenoids into advanced positions in which they retain the corresponding programming levers in their operative positions; and a common beater operable in time with the rotary motion of the cam box for moving all of the programming levers into their operative positions preparatory to each selective energization of the solenoids.

4. A circular knitting machine according to claim 3, which also includes a beater common to all of the latches and operable in time with the rotary motion of the cam box for returning advanced latches to their original positions after each selective energization of the solenoids.

5. A circular knitting machine according to claim 1, which also includes a rotary component carrying a plurality of mag nets, the reed switch being stationarily located and held adjacent to the rotary component so that it is influenced by the magnets, a bank of selectively movable programming levers each movable into an operative position in which it can strike and render operative a corresponding actuator of a selector member; a corresponding number of latches arranged to be selectively projected by selectively energized solenoids into advanced positions in which they retain the corresponding programming levers in their operative positions, a common beater for moving all of the programming levers into their operative positions preparatory to each selective energization of the solenoids, a second beater common to all of the latches for returning advanced latches to their original positions after each selective energization of the solenoids, a spindle to which the aforementioned rotary component carrying magnets is secured, a gear combined with said spindle, intermediate gearing between said gear and a gear on a cam box carriage, cams secured to the gear combined with the spindle for controlling movements of the beaters for the programming levers and the latches respectively whereby the said rotary component and the beaters are all operable in time with the rotary motion of the cam box.

6. A circular knitting machine according to claim 1, which includes a control drum over which the film is passed, said drum comprising two axially spaced and intermittently rotatable end portions having spikes engaging holes in the margins of the film, and an intermediate stationary cylindrical portion which is hollow and has formed therein an axial row of holes; pawl and ratchet means for intermittently rotating the end portions of the drum and so racking on the film in steps; light emitting means on the outside of the drum; and, set in register with the holes in said drum, a row of the photoelectric cells each of which is wired up to an electronic thyristor switch device, the arrangement being such that each time the film is racked on one step a fresh transverse line of apertures in and unapertured portions of the film will be brought into coincidence with the axial row of holes in the drum.

7. A circular knitting machine according to claim I, wherein the timer circuit comprises a capacitor and a resistance wired in circuit with a transistor, so that each time the reed switch is closed the capacitor is charged and when said switch is next released and opened the capacitor discharges into the transistor for a preset length of time determined by the capacitor/voltage/resistance characteristic to thereby cause said pulse of current to pass to the solenoids. 

1. A circular knitting machine comprising, in combination, a stationary tricked cylinder; knitting instruments in said cylinder having butts thereon; a cam box revolvable about said cylinder and fitted with cams for actuating the knitting instruments; a plurality of patterning units rotatable in unison with said cam box, each of these units including a stack of individually movable selector members for action selectively upoN the aforesaid butts for actuating knitting instruments selectively, and a corresponding stack of actuators for selectively actuating the selector members of the unit; a bank of solenoids at a stationary location for effecting selective actuation of the actuators; switch means arranged in circuitry incorporating the solenoids; a relatively thin and flexible control film having formed therein dispositions of holes predetermined in accordance with the pattern it is desired to produce on the machine; and means for intermittently moving said control film in time with the rotary cam box suchwise that the apertured and unapertured portions of the film influence the operation of said switch means, wherein the improvement resides in the provision in the machine of electronic thyristor switch devices for controlling energization of the corresponding solenoids; photoelectric cells arranged to sense holes in the film to dictate selective preconditioning of the said electronic thyristor devices, in readiness for their being rendered operative to cause a pulse of current to be passed to the solenoids, wherein there is provided a separate photoelectric cell and a separate thyristor device for each solenoid, a timer circuit for rendering the selectively preconditioned electronic thyristor switch devices operative for a preset length of time and as a consequence energizing the solenoids for the same length of time; and a reed switch which is regularly operated in timed relation with the rotary motion of the cam box for controlling the said timer circuit.
 2. A circular knitting machine according to claim 1, which includes a rotary component carrying a plurality of magnets, and gearing between a rotary cam box carriage and said rotary component for driving the latter in time with the rotary motion of the cam box, the reed switch being stationarily located and held adjacent to the rotary component so that it is influenced by the magnets.
 3. A circular knitting machine according to claim 1, which includes a bank of selectively movable programming levers each movable into an operative position in which it can strike and render operative a corresponding actuator of a selector member; a corresponding number of latches arranged to be selectively projected by selectively energized solenoids into advanced positions in which they retain the corresponding programming levers in their operative positions; and a common beater operable in time with the rotary motion of the cam box for moving all of the programming levers into their operative positions preparatory to each selective energization of the solenoids.
 4. A circular knitting machine according to claim 3, which also includes a beater common to all of the latches and operable in time with the rotary motion of the cam box for returning advanced latches to their original positions after each selective energization of the solenoids.
 5. A circular knitting machine according to claim 1, which also includes a rotary component carrying a plurality of magnets, the reed switch being stationarily located and held adjacent to the rotary component so that it is influenced by the magnets, a bank of selectively movable programming levers each movable into an operative position in which it can strike and render operative a corresponding actuator of a selector member; a corresponding number of latches arranged to be selectively projected by selectively energized solenoids into advanced positions in which they retain the corresponding programming levers in their operative positions, a common beater for moving all of the programming levers into their operative positions preparatory to each selective energization of the solenoids, a second beater common to all of the latches for returning advanced latches to their original positions after each selective energization of the solenoids, a spindle to which the aforementioned rotary component carrying magnets is secured, a gear combined with said spindle, intermediate gearing between said gear and a gear on a Cam box carriage, cams secured to the gear combined with the spindle for controlling movements of the beaters for the programming levers and the latches respectively whereby the said rotary component and the beaters are all operable in time with the rotary motion of the cam box.
 6. A circular knitting machine according to claim 1, which includes a control drum over which the film is passed, said drum comprising two axially spaced and intermittently rotatable end portions having spikes engaging holes in the margins of the film, and an intermediate stationary cylindrical portion which is hollow and has formed therein an axial row of holes; pawl and ratchet means for intermittently rotating the end portions of the drum and so racking on the film in steps; light emitting means on the outside of the drum; and, set in register with the holes in said drum, a row of the photoelectric cells each of which is wired up to an electronic thyristor switch device, the arrangement being such that each time the film is racked on one step a fresh transverse line of apertures in and unapertured portions of the film will be brought into coincidence with the axial row of holes in the drum.
 7. A circular knitting machine according to claim 1, wherein the timer circuit comprises a capacitor and a resistance wired in circuit with a transistor, so that each time the reed switch is closed the capacitor is charged and when said switch is next released and opened the capacitor discharges into the transistor for a preset length of time determined by the capacitor/voltage/resistance characteristic to thereby cause said pulse of current to pass to the solenoids. 